That transaction had been quite successful.
After all, the remains of the Sun King Ruins had already been excavated when they dismantled the traps. The most precious resources, knowledge, and equipment had already been shipped back to the Black Tower.
The Sun King Ruins were only an empty shell. He obviously made a profit by trading it for a 8-Formula Meditation Law Set.
The Black Tower's power greatly increased in the half year after obtaining that Meditation Law Set. Harren really wanted to thank the young mage for this, but he felt a bit embarrassed about the matter of the Sun King Ruins...
But this was the request the young mage had raised himself, so Harren couldn't be blamed for fleecing him.